Various electronic design automation (EDA) tools generate, optimize and verify designs for semiconductor devices while ensuring that the design and manufacturing specifications are met. In near-wavelength and sub-wavelength photolithography, other EDA tools use optical proximity correction (OPC) and thereby modify photolithographic masks for integrated circuits (ICs). OPC includes rule-based OPC and model-based OPC. Note that the term OPC as used herein can generically refer to proximity effect corrections, e.g. for resist, etch, and micro-loading.
Typically, OPC is performed toward the end of the chip design process, at a point at which a design package of an integrated circuit (IC) (which includes one or more devices and/or one or more circuit elements represented as multiple physical layout layers) is ready for dissection into segments. In general, compared to rule-based OPC, model-based OPC provides higher accuracy but is computationally more expensive and takes significantly more time to process each of the multiple physical layout layers.